作者:Lande Zhang、Feng Liang、Lingzhi Sun、Yuefei Hu、Hongwen Hu
DOI:10.1055/s-2000-8195
日期:——
A novel and practical procedure for the preparation of 3-unsubstituted indolizines by 1,3-dipolar cycloaddition was developed. The requisite pyridinium N-methylides were generated simply from the corresponding N-(carboxymethyl)pyridinium halides. In the presence of MnO2, electron-deficient alkenes, instead of alkynes or vinyl bromides, were used successfully as dipolarophiles. This general method features cheap reagents, simple workup procedure and gives the products in moderate to high yields (57-92%).
开发了一种新颖且实用的制备3-无取代吲哚啉的程序,采用1,3-极性环加成反应。所需的吡啶二甲基化物简单地通过相应的N-(羧基甲基)吡啶卤化物生成。在MnO2存在下,成功地将电子缺乏的烯烃用作极性加成体,而非炔烃或乙烯溴化物。该通用方法具有试剂廉价、后处理简单,并且产物的产率中等至较高(57-92%)。